老年人根管治疗疗效的相关因素

目的:研究老年人根管治疗疗效及其影响因素.方法:对56例65岁以上老年人,根管治疗后2年以上的126颗牙齿进行检查,按治疗后年限分3组:2～3年组,4～5年组,6年以上组.应用根尖周指数(Periodicalindex)评定X线片和综合临床检查,对其治疗进行评价.结果:老年人根管治疗成功率为72.2%;三组间根管治疗成功率差异无显著性.恰填根管治疗的成功率(82.2%)比欠填和超填的成功率(47.2%)要高;恰填病例中,冠方修复体质量好的患牙比质量差的患牙根尖周炎发病率低(25.7%和58.4%);去除欠填和超填病例后,桩冠修复患牙的根管治疗成功率为58.8%,而未做桩冠修复的患牙成功率为87.5%.结论:根充质量、冠方修复体质量、桩冠修复是影响老年人根管治疗疗效的主要因素.     

根管治疗术远期疗效的影响因素

根管治疗术（root canal therapy,RCT）是治疗牙髓病、根尖周病的主要方法.影响根管治疗术远期疗效的因素较多,而RCT前根尖周状态和根充位置是两大主要因素.     

Susceptibility of Nd:YAG laser-irradiated root surfaces in replanted teeth to external inflammatory resorption

Abstract— NdYAG laser-induced modification of the root surface may inhibit development of external inflammatory resorption in replanted teeth. This study tested this hypothesis in vivo. The pulp chambers of six mandibular premolars in each of two dogs were accessed, inoculated with plaque, and sealed (Groups 1, 2). Two additional premolars in each dog were endodontically treated without inoculation (Groups 3, 4). After 2 weeks, teeth were hemisected and extracted. Each root had a 2times3 mm surface area denuded of cementum on the buccal and lingual surface. In Groups 1 (n= 12 roots) and 3 (n=4), the denuded surfaces were wiped with 15% EDTA, coated with black ink, and irradiated with Nd:YAG laser (0.75 W, 15 ppc, 300 pm tip, 20 s). In Groups 2 (n= 12) and 4 (n= 4), the surfaces were wiped with 15% EDTA, and rinsed with sterile saline for 20 s. Roots were replanted within 5 min. The dogs were perfwion-euthanised 10 weeks after replantation. Block specimens were removed, decalcified, embedded and horizontally sectioned (6 pm) at 180-pm intervals, resulting in 10 to 14 cross-sections of each root. From these, the middle five consecutive sections were stained with hematoxylin and eosin, and observed by light microscopy for occurrence of surface, inflammatory and replacement resorption on the denuded surfaces. No obvious differences were noted between the laser-irradiated and non-irradiated surfaces. Inflammatory resorption was frequent in Groups 1 and 2, and absent in Groups 3 and 4. Replacement resorption was minimal in Groups 1 and 2, and frequent in Groups 3 and 4. Differences between Groups 1 and 2, and between Groups 3 and 4 were not significant, whereas the differences between the two pairs of groups were statistically significant (chi-square and two-way ANOVA, P>0.006). These results did not support the hypothesis, and questioned the clinical validity of the surface modification in NdYAG laser-irradiated den-tin. Therefore, the clinical application of NdYAG laser to the root surfaces of replanted teeth is not warranted.     

Chronic opioid treatment of neuroblastoma X dorsal root ganglion neuron hybrid F11 cells results in elevated GM1 ganglioside and cyclic adenosine monophosphate levels and onset of naloxone-evoked decreases in membrane K+ currents

Prolongation of the action potential duration of dorsal root ganglion (DRG) neurons by low (nM) concentrations of opioids occurs through activation of excitatory opioid receptors that are positively coupled via G_s regulatory protein to adenylate cyclase. Previous results suggested GM1 ganglioside to have an essential role in regulating this excitatory response, but not the inhibitory (APD-shortening) response to higher (μM) opioid concentrations. Furthermore, it was proposed that synthesis of GM1 is upregulated by prolonged activation of excitatory opioid receptor functions. To explore this possibility we have utilized cultures of hybrid F11 cells to carry out closely correlated electrophysiological and biochemical analyses of the effects of chronic opioid treatment on a homogeneous population of clonal cells which express many functions characteristic of DRG neurons. We show that chronic opioid exposure of F11 cells does, in fact, result in elevated levels of GM1 as well as cyclic adenosine monophosphate (AMP), concomitant with the onset of opioid excitatory supersensitivity as manifested by naloxone-evoked decreases in voltage-dependent membrane K⁺ currents. Such elevation of GM1 would be expected to enhance the efficacy of excitatory opioid receptor activation of the G_s/adenylate cyclase/cyclic AMP system, thereby providing a positive feedback mechanism that may account for the remarkable supersensitivity of chronic opioid-treated neurons to the excitatory effects of opioid agonists as well as antagonists. These in vitro findings may provide novel insights into the mechanisms underlying naloxone-precipitated withdrawal syndromes and opioid-induced hyperalgesia after chronic opiatf addiction in vivo. © 1995 Wiley-Liss, Inc.     

S100 protein-immunoreactive primary sensory neurons in the trigeminal and dorsal root ganglia of the rat

The cell body size (cross-sectional area) of S100-immunoreactive (-ir) primary neurons was measured in the trigeminal (TG) and lumbar dorsal root ganglia (DRG). About a half of neurons exhibited S100-immunoreactivity (-ir) in the DRG (44.0%) and TG (59.0%). DRG neurons with cell bodies >1200 μm² mostly exhibited S100-ir (96.5%), whereas S100-ir DRG neurons <600 μm² were rare (8.0%). 36.6% of DRG neurons in the cell size range 600–1200 μm² showed the ir. TG neurons >800 μm² mostly exhibited S100-ir (93.1%), whereas those <400 μm² were devoid of it (positive cells 10.5%). 58.3% of TG cells in the range 400–800 μm² contained S100-ir. Double-immunofluorescence method revealed the co-expression of S100 and other calcium-binding proteins. Parvalbumin-ir neurons mostly exhibited S100-ir in the DRG (97.4%) and TG (97.0%). The co-expression of S100 and calbindin D-28k was very rare in the DRG, because the DRG contained few calbindin D-28k-ir neurons. Unlike in the DRG, numerous neurons co-expressed S100- and calbindin D-28k-ir in the TG. Most calbindin D-28k-ir TG neurons were also immunoreactive for S100 (90.7%). Sub-populations of calretinin (CR)-ir neurons co-expressed S100-ir in both the DRG (68%) and TG (50.0%). Virtually all CR-ir neurons >1400 μm² co-expressed S100-ir in the DRG (100%) and TG (95.9%). CR-ir neurons <800 μm² were rarely exhibited S100-ir (DRG 18.0%, TG 21.9%). 71.3 and 60.5% of CR-ir neurons in the range 800–1400 μm² co-expressed S100-ir in the DRG and TG, respectively. The present study indicates that S100 is closely correlated to the primary neuronal cell size in the DRG and TG.     

应用同种动脉治疗主动脉根部病变

报告５例采用同种动脉（ＨＡＶ）治疗５例主动脉根部病变（主动脉瓣狭窄１例，关闭不全４例）。男３例，女２例；年龄１３～４７岁。病因为细菌性心内膜炎２例（包括先天主动脉瓣二瓣化畸型１例），Ｍａｒｆａｎ综合征２例，风湿性主动脉瓣关闭不全１例。术中采用同种主动脉全根置换３例（Ｂｅｎｔａｌｌ手术），其中１例用ＨＡＶ上的二尖瓣前叶加宽主动脉瓣环（Ｍａｎｏｕｇｕｉａｎ手术），余２例用自体肺动脉移置主动脉根部，另取同种肺动脉做原位移置（Ｒｏｓｓ手术）。结果死亡１冽，４例存活，且无并发症发生。术后超声心动图提示主动脉根部良好，无主动脉瓣反流。随访２．５～３．５年疗效满意。     

Antisperm antibodies and lymphocyte subsets in semen—not a simple relationship

The significance of white blood cells in the ejaculate remains a matter of controversy. Several authors have suggested that such cells are important in the modulation of an antisperm antibody response, i.e. a predominance of suppressor/cytotoxic to helper/inducer T cells may prevent the development of antisperm antibodies. In order to examine this relationship further we have documented the white blood cell types, with emphasis on the T-lymphocyte populations, in the ejaculates of men from infertile couples with and without antisperm antibodies; the latter group was divided further into two groups--vasovasostomized men and idiopathic men. All seven of the men without antisperm antibodies had a predominance of suppressor/cytotoxic T cells to helper/inducer T cells in the ejaculate. However, only in some of the men with antibodies was there a predominance of T-helper/inducer cells. It is clear that the relationship between antisperm antibodies and seminal leucocytes is therefore not as straightforward as has been proposed.     

The stimulant effect of modafinil on wakefulness is not associated with an increase in anxiety in mice

Modafinil is a new drug used in the treatment of narcolepsy. Its administration in mice induced a dose-dependent increase in locomotor activity. The effects of modafinil were compared with those of dexamphetamine on three tests that assessed the anxiety level (drugs were used at doses which induced a roughly similar stimulation of locomotor activity). Dexamphetamine increased the latency of exploration of a white compartment, increased thigmotaxis in an open-field and decreased the time spent in the open arms of an elevated plus-maze. None of these responses was significantly modified by modafinil. We conclude that modafinil does not share the anxiogenic effects of dexamphetamine.     

Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation

Although relatively high CO2 laser energies have been shown to sterilize root canals, the response of several bacterial strains to decreasing exposures of CO2 laser energy remains unknown. Freshly grown bacterial cells were irradiated on glass microscope coverslips. A comparison of equivalent energy exposures with differing parameters was made on the bacterial viability. No statistically significant difference was found in the energy required to kill closely related bacterial species. However, the energy density required to kill greater than 99.5% of the bacteria is less than 200 J/cm2, much less than that shown to sterilize in a previous study.     

握力大小与前臂肌肉表面肌电活动模式的相关性研究

目的 研究手部握力大小与前臂肌肉表面肌电信号特征的相关性.方法 9名健康被试者参加了试验,包括最大自主收缩力(maximum volunteer contraction,MVC),80% MVC及40% MVC,记录指浅屈肌和腕长伸肌的表面肌电信号,并采用均方根和小波分析方法提取其特征参数;运用SPSS软件统计以被试者自身的MVC为基准的不同握力水平的相对特征值,使不同的被试者具有可比性.结果 对于单个被试者握力水平与表面肌电活动模式存在正相关性,即握力越大则对应的表面肌电信号的特征值也越大;对于所有的被试者这种正相关性也存在.结论 握力水平与肌肉活动模式具有相关性,这提示通过表面肌电信号的特征值不但可以预测握力的大小,还可用于运动功能测试及康复的评价.